The invention relates to machine tools and more particularly, to a device for housing and changing tools onto a machine tool spindle.
A tool changing device of the type defined, for example, in DE 43 31 064 A1, consists of a transport device which can be moved along two horizontal linear guides and along a third vertical linear guide between a magazine (storage area) hand-over position and a spindle hand-over position. The transport device holds a tool housing with two gripping devices which can swivel on an axis perpendicular to the vertical driving direction and the spindle axis, between the spindle hand-over position, with horizontal alignment of the tool, and the vertical magazine hand-over position. The swivelling movement derives from the movement of the transport device on a sliding guide.
For the transport of the tool, therefore, three driving axis and at least one rotating axis are needed. A tool changing device of this kind is costly and expensive. Moreover, it requires a lot of space.
Another known tool changing device is disclosed in DE 40 09 537 C2 and includes a transport device which can be moved along one single linear guide between one hand-over position close to a magazine and a spindle hand-over position. The transport device holds a tool housing with two gripping devices that can swivel on an axis parallel to the driving direction, between the spindle hand-over position, with horizontal alignment of the tool, and the vertical magazine hand-over position. The swivelling movement derives on a control guide from the movement of the transport device, which occurs between the magazine hand-over position and the spindle hand-over position, by means of a toothed rack gear unit.
In the known device, the tools must be exchanged between the magazine and the tool housing staying in the stored hand-over position by means of a special handling robot. The toothed rack gear unit and the additional handling robot make the device significantly more expensive.
Accordingly, the present invention features a tool changing device which is simpler, cheaper and less susceptible to faults than the known types. The tool changing device of the present invention has only one single driving device for transporting the tool. The transport direction can be chosen in such a way that with the transport movement a tool can be placed directly into a tool casing in the magazine. In one transporting motion, the tool is brought to the spindle hand-over position. To swivel the tool in the spindle direction no rotation gear is needed.
In a preferred embodiment, the tool changing time can be significantly reduced by arranging two transport devices next to each other, one of which places the used operating tool held in the tool spindle in a spindle hand-over position and stores it into an empty storage place in the tool magazine, while the other transport device keeps a new operating tool, taken from the tool magazine, ready for coupling to the tool spindle in the spindle hand-over position.
The present invention features a machine tool changing device for a tool machine having at least one tool spindle and with which a machine tool can be coupled in a spindle hand-over position aligned along a machine tool hand-over spindle axis. The machine tool changing device includes a tool magazine in which is located at least one machine tool to be changed and engaged with the tool machine spindle. The at least one machine tool includes a rotation axis and is housed with an orientation wherein the rotation axis is diverging from the machine tool hand-over spindle axis.
The present invention also includes a transport device moving only in a transport direction which is parallel to the rotation axis of a stored machine tool for an entire transport cycle and including a machine tool holder which swivels the machine tool during its transport between a stored position and the spindle hand-over position along a guide path about a swiveling axis. The transport device moves along a transport guide between the stored position and the spindle hand-over position. The swiveling axis is perpendicular to the transport direction and the spindle axis.